Electrical connecter



1933- JOHNSON El AL 1,922,686

} ELECTRICAL CONNECTER Filed May 4, 192

ymofld Johnson 67 Me 7." S/ebs Patented Aug. 15, 1933 UNITED STATES PATENT ,OFFIC ELECTRICAL CONNECTER Raymond Johnson, Brooklyn, N.

Theodore Sicbs, Nutley, N. J

Company,

Western Electric Y., and Claude assignors to Incorporated,

. 1 Claim.

This invention relates to electrical connecters, and more particularly to a strain relief connection for an electrical plug.

Heretofore, in some instances, considerable difficulty has been encountered in maintaining a serviceable electrical connection between a flexible conductor and an electrical plug which is adapted to be inserted into a companion jack or socket member. In disconnecting such an electrical circuit there is a tendency for an operator to grasp and pull on the installed flexible conductor to remove the plug from its socket. This longitudinal pull on -the conducting wire produces a direct stress on the wire-terminal connection thereby eventually resulting in a weak and troublesome electrical junction of the conductor with the plug.

The primary object of this invention is to provide a simple and sturdy device for gripping an electrical conductor to relieve a connecting terminal thereof from stress.

In accordance with one embodiment, the invention contemplates an electrical plug in which the adjacent portion of an insulated conductor connected thereto is embraced by a self -tightening clamping member adapted to engage the body of the plug whereby all stresses introduced into the conductor are taken up byithe clamping mem-v ber to prevent them from reaching the electrical connection.

It is believed that a complete understanding of the invention may be had by reference to the following description taken in conjunction with the accompanying drawing illustrating one embodiment of the invention, in which,

Fig. 1 is an elevational view of an electrical plug incorporating the invention,

Fig. 2 is a longitudinal sectional view taken on line 22 of Fig. 1, and

Fig. 3 is an enlarged transverse sectional view taken on line 33 of Fig. 2.

Referring to the drawing in which similar reference characters represent the same parts in the several views, the numeral 10 designates an electrical conducting tip having an enlarged externally threaded base portion 11. This base portion has a central bore 12 into which is inserted a stranded conductor 13 which may be composed of tinned copper or other suitable conducting material and secured therein by a set screw 14 threaded radially through the cylindrical wall of the base 11. Substantially surrounding a rubber covering 17 of the conductor 13 adjacent the base portion 11 are mounted a pair of externally tapered semi-circular sleeve 20-20 An internala hard rubber tubular shell 24 having a shoulder 23. As the plug is screwed down tightly in the shell 24 the cylindrical member abuts the shoulder 23 and is forced up over the gripping sleeves to increase the intensity of the clamping action on the conductor. The rear end of the tubular member 24 is provided with a flared opening 25 some distance from where the conductor is clamped so as to lessen the probability of fatigue and the abrasion of the insulation, and also to prevent any sharp bending of the conductor near or.adjacent the clamping members. From the foregoing it will be readily understood.that any longitudinal pull or stress on the conductor 13 such as may occur if the operator may attempt to remove the plug from its jack by grasping the conductor will be absorbed by the clamping members 20-21. In fact as the intensity of the pull on the conductor increases the clamping action of the gripping sleeves 20-20 increases cal member 21 abutting the shoulder 23 being forced still further over the semi-circular sleeves.

In disassembling the plug the tubular shell 24 is unscrewed from the enlarged portion 11 of the tip 10 and pushed back on the insulated conductor 13. This affords access to the set screw 14 which is removed, thereby releasing and permitting the disconnecting of the tip 10 from the conductor 13. The cylindrical member 21 can then be easily slipped off of the semi-circular sleeve 20 thereby resulting in a complete disassembly of the plug.

It will be understood that the embodiment of the invention herein described and illustrated is merely a convenient and useful form of the invention which is capable of many other modifications without departing from the spirit and scope of the invention as defined by the appended claim. 1

What is claimed is:

In an electrical plug adapted to be electrically connected to an insulated conductor, an electrical conducting tip having an externally threaded base portion with a bore therein for receiving the conductor, a shell of insulating material having an aperture in one end thereof for receiving the insulated conductor, a threaded bore in" the other end thereof for receiving the threaded base portion of the tip, and a second aperture larger than due to the cylindriover said segments to effect a clamping action on said insulated conductor, said clamping device adapted to be secured in the second mentioned aperture with the ends thereof against the shoulder in the shell and the base portion of the tip.

RAYMOND JOHNSON. CLAUDE THEODORE SIEBS. 

